Manufacture of halogen derivatives of organic compounds.



UNITED STATES PATENT @FFIQE.

WILLIAM HENRY PERKIN, CHARLES WEIZMANN, AND HAROLD DAVIES, OF

MANCHESTER, ENGLAND.

MANUFACTURE OF HALOGEN DERIVATIVES QF ORGANIC COMPOUNDS.

No Drawing.

To all whom it may concern Bt' it known that we, WILLIAM HENRY PERKIN and CHARLES WEIZMANN, both subjects of the King of Great Britain and Ireland, and residents of The University, Manchester, in the countyof Lancaster, England, and HAROLD DAvms, a subject of the King of Great Britain and Ireland, of 5 West Grove, Manchester, aforesaid, have invented new and useful Improvements in the Manufacture of Halogen Derivatives of Organic Compounds, of which the following is a specification We have found that if we halogenate vapors of organic compounds and regulate the access of halogen in such manner as to use it up immediately it comes into contact with the vapors of the organic compound and in such manner as to permit of the removal of the desired product, the formation of higher halides than that desired can be lessened, or almost entirely prevented, according to the efiiciency of the means of removal, and the amount formed is very much less than that formed if the same quantity of halogen be passed'into the liquid. Moreover, the product of the reaction can, when required, by fractional distillation, be separated into definite fractions each containing a definite halogen substitution product which can be identified and obtained in a high state of purity.

According to our present invention therefore we take the body to be halogenated and vaporize it' and subject the vapor to the vapor'of the halogen in suchmanner that vapor' of the halogen is immediately consumed and the required product, as it is formed, is removedfrom the zone of reaction, there being always an excess of the vapor of the body to be halogenated and a minimum of thereqttired product present in the reaction area.

The process'may be carried out by passing a stream of vapor of the halogen into a tube, or vessel, through which a stream of the vapor" of the body .being treated passes, larger in quantity than the theoretical amount required to combine with the halogen, the productformed condensing and passing atoncefrom the zone of reaction and the product can then be fractionated a'n'd the insufficiently halogenated fraQfiOns be again-subjected to "the reaction.

Specification of Letters Patent.

Patented June 22, 1915.

The apparatus for carrying out this invention may be such as is described in either the application for British Letters Patent No. 13,051/12, or No. 22,737/12, one form of such an apparatus being described and illustrated in the paper by Prof. Perkin in the Journal of the Society of Chemical Inclustry, July 15th, 1912, but we do not limit ourselves to the use of such apparatus.

The reaction can, if desired, be accelerated by heat, or light,or by other agents which assist halogenation, such for example as phosphorus compounds, or iodin.

It has been proposed to mix halogen with vapors of organic bodies and then treat the mixture so as to cause combination to take place, but we have found that the presence of such a mixture is disadvantageous and causes a risk of explosion. In the process now described the combination of-the halogen with tho hydrogen should be so nearly instantaneous that the vapors in the reaction chamber are not perceptibly tinged with halogen. To attain this end it is sometimes necessary to accelerate the reaction by the aid of light or other known means particularly when treating low boiling liquids and at the commencement of the process. In many cases however such acceleration is unnecessary and the halogenation proceeds.

are vaporized and chlorinated in the aforesaid apparatus until the mixture of iso-amyl chlorid and the higher chlorids produced boils at about 130 centigrade (as shown by a thermometer immersed in the liquid). The product is then,'-by fractional distillation, separated into the following portions, namely; (1) A'portion'boiling'below about l. 0 Centigrade and containing. conslderable A residue which contains trichlorids, or

higher chlorids.

The portions (2) and (3) contain principally dichlorids and may be fractionated in' any known, or suitable, manner, yielding three main fractions, namely:

(A.) A fraction of a boiling polnt about 142 centigrade corresponding to the formula (B.) A fraction of a boiling point about 150 centigrade' correspondlng to the formula ((3.) A fraction of a boiling point about 170172 centigrade corresponding to the formula oH-oBrothel.

CHa

The constitution of the fraction A was proved by eliminating from it two molecular proportions of hydrochloric acid and so transforming it into iso-propylacetylene which, on treatment with aqueous mercuric bromid, and on decomposition of the double compound formed, yielded methyl-isopropyl-ketone which was characterized by its semi-carbazone.

The constitution of the fraction B was proved by eliminating two ,molecular proportions of hydrochloric acid-thus producing isoprene, which was identified by transforming it into the dibrom-hydrin melting at 86 centigrade. The isoprene so obtained, when submitted to polymerization, resulted in a caoutchouc-like mass. The dichlorid was found to be identical with the isoprene dihydrochlorid obtained by Ipatiew by the addition of two molecular proportions of hydrochloric-acid to unsymmetrical dimethyl-allene.

The constitution of the fraction 0 was proved by transforming it into a di-nitrile by boiling it with alcoholic potassium cyanid. This di-nitrile, which boils at about 155 centigrade (11 mm.) gave, on hydrolysis, a dibasic acid identical with betamethyl-adipic acid. On heating the fraction C with anhydrous potassium acetate in glacial acetic acid and distilling the prod-- uct, a diacetate was obtained which boiled at about 116117 centigrade (17 mm.). This diacetate, on hydrolysis, yielded a glycol boiliig at- 124125 centigrade (13 mm.) which, on treatment with phenyl iso-cyanate, gave a diphenyl diurethane of a melting point of 97 centigrade. The diacetate,

the glycol, and the urethane, are identical Example 2P1'epa1'ati0n of 1.2.3.4-tet1'achl0-buta /Le.S eventy-eight parts by weight of butyl-chlorid are subjected to the action of chlorin in the presence of ultraviolet rays, until the mass has increased by sixty parts by weight. The product is then subjected to fractional distillation under reduced pressure after separation of unaltered butylchlorid, the result of this fractignal distillation under a pressure of fifteen'millimeters was found to be as follows: Of fraction I, which distilled off between 55 and 74 centigrade, there were thirteen parts; of fraction II, which distilled off between 74 and 90 centigrade, there were forty-nine parts; of fraction III, which distilled ofl between 90 and 95 centigrade, there were sixteen parts, and of fraction IV, which distilled off between 95 and 105 centigrade, there were eight parts. The residue consisted of seven parts.

Fraction II consisted of a mixture of trichloro and tetra-chloro bodies.

Fraction III consisted of a pure tetrachloro body which yielded divinyl on treatment with zinc dust and alcohol and the divinyl thus obtained was identified by means of its tetra-bromid.

Example 3P1'0lu0tz'0n of monochlor heptane.300 grams of normal heptane of boiling point 96100 centigrade are chlorinated in the aforesaid apparatus until the weight increases to 350 grams, the temperature in the vessel of reaction being 90 centigrade. Bythis means we obtained 224 grams of unchanged heptane, 116 grams of monochlor-heptane and 10 grams of dichlorheptane, the formation of the dichlorids being thus only 3 per cent. of the amount of normal heptane used. The temperature of the mixed vapors and gases in the zone of reaction is below the boiling point of the heptane owing to the presence of the other substances entering into the reaction. Their combined vapor pressures are equal to atmospheric pressure since there is a reflux condenser above the reaction chamber.

Example 4Pzeparatz'on of dz'bz-om-z'sopentane.Iso-amyl-bromid of boiling point 120 centigrade is vaporized and heated with a stream of bromid vapor and air in the presence of light until a thermometer imuid obtained as the result of the reaction is then fractionated under reduced. pressure and'yields unchanged monobromid together with dibromids, principally .1.3-dibrom-iso'- pentane of boiling po1nt 72 to 75 at a pressure of 15 mm.

Example 5Preparatz'on of mono-071,107- acetic acid.An excess of vapor of acetic acid is passed through a glass, or silica, tube,

into which also a stream of chlorin is passed, a powerful source of chemically active light being situated near the said tube. The vapors are condensed and fractionated and unaltered acetic acid again treated.

What we claim is:-

1. The manufacture of dichloro derivatives of paraffin hydrocarbons having the chlorin attached to different carbon atoms by causing a halogen to react with vapors of a mono-chlorinated paraflin hydrocarbon while regulating the access of the halogen so that it is used up immediately it comes into contact with said vapors, substantially as described.

2. The manufacture of dichloro derivatives of paraflin hydrocarbons having the chlorin attached to diflerent carbon atoms by causing a halogen to react with vapors of a mono-chlorinated parafiin hydrocarbon while regulating the access'of the halogen so that it is used up immediately it comes into contact with said vapors removing the and Charles Weizmann:

desired halogenated product as itis formed and subjecting it to fractional distillation.

3. The manufacture of dihalogen-derivatives of hydrocarbons havingthe halogen atoms attached to different carbon atoms, by causmg a halogen to react with vapors of a mono-halogen-hydrocarbon while regulating the'access of the halogen so that it is used up immediately it comes into contact with the said vapors.

4. The manufacture of dichloro-derivatives of hydrocarbons having the chlorin atom attached to difierent carbon atoms, by causing chlorin to react with vapors of a monochloro-hydrocarbon while regulating the access of chlorin sothat it is used up immediately it comes into contact with the i said vapors.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

.WILLIAM HENRY PERKIN. CHARLES WEIZMANN. I Witnesses as to William Henry Perkin MALCOLM 'SMnKUnRsT, v Gnonon WEAVER.

HAROLD DAVIES. Witnesses as to Harold Davies:

0. J. WORTH, O, P. LIDDON. 

